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Conference Proceedings National Telesystems Conference 1993

16-17 June 1993

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Displaying Results 1 - 25 of 45
  • The RADARSAT remote sensing ground station for McMurdo station, Antarctica

    Publication Year: 1993
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (37 KB)

    Summary form only given. Under a memorandum of agreement with the Canadian Space Agency and NOAA, NASA has agreed to construct a remote sensing station and deploy it at McMurdo Base in Antarctica. The station is designed to receive the downlinked data from RADARSAT and to provide for future remote sensing applications on the Antarctica continent. The system, which was designed to meet the special ... View full abstract»

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  • A large W-band slotted waveguide array

    Publication Year: 1993
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (36 KB)

    Summary form only given. Slotted arrays at millimeter-wave frequencies play an important role in commercial applications such as collision radars and synthetic vision systems. The authors describe the design, fabrication and testing of a 3-ft-long slotted waveguide array having 600 edge wall slots. The design represents a low-loss technique for achieving a high-resolution pattern and uses a standa... View full abstract»

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  • A GPS solution to precision approach and landing (even in the presence of anti-spoofing)

    Publication Year: 1993
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (64 KB)

    Summary form only given. The ability to track quality dual-frequency P-code (code and phase) observables has been responsible for many exciting developments in global positioning system (GPS) geodesy and precision navigation. However, civilian users were confronted with the fact that P-code quality tracking will essentially disappear when the government enacts full time anti-spoofing (AS). A propr... View full abstract»

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  • INTELSAT VIII; INTELSAT's next generation satellite

    Publication Year: 1993
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (74 KB)

    Summary form only given. The authors present a general overview of the design and key features of Intelsat's next-generation satellite, INTELSAT VIII. INTELSAT VIII will provide both C-band and Ku-band services through a complex antenna system. The 3700-kg spacecraft is based on the GE Series 7000 platform currently in production and is expected to provide over 13 years of in-orbit operational ser... View full abstract»

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  • Prospects for international TVRO growth

    Publication Year: 1993
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (31 KB)

    Summary form only given, as follows. With the introduction at the end of 1993 of the high EIRP INTELSAT VII/VIII-A satellites, the INTELSAT network is about to enter a new phase of dramatically increased capability. Voice, data and video services will become practical on global scale to much smaller ground terminals than ever before. A similar situation occurred in the United States in the late 19... View full abstract»

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  • Externally modulated optical analog links for microwave applications

    Publication Year: 1993
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (37 KB)

    Summary form only given, as follows. Fiber-optic analog links using external modulators are useful for microwave applications. They can transmit microwave signals over distances up to several kilometers with low loss and negligible dispersion. With the addition of a few more components, these links can be used in phased array antennas to steer the beam and to provide broadband adaptive nulling. Th... View full abstract»

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  • Proceedings of 1993 IEEE National Telesystems Conference

    Publication Year: 1993
    Request permission for commercial reuse | PDF file iconPDF (96 KB)
    Freely Available from IEEE
  • MMW technology for enhanced situation awareness/enhanced vision systems

    Publication Year: 1993, Page(s):97 - 99
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (272 KB)

    Millimeter wave (MMW) radar systems are now demonstrating the ability to image airport environments in fog. The authors discuss the use of MMW radar technology to provide pilots with enhanced vision and enhanced situation awareness. One of the first steps in providing an autonomous aircraft is the Enhanced Vision System (EVS). This system consists of a heads-up display (HUD) and an imaging MMW rad... View full abstract»

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  • Autonomous precision approach and landing system APALS

    Publication Year: 1993, Page(s):101 - 107
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (492 KB)

    The autonomous precision approach and landing system (APALS) system is a precision approach and landing system designed to enable low-visibility landings at many more airports than is now possible. It is an autonomous navigation system which uses standard avionics equipment to determine the aircraft position and altitude with respect to unique terrain features over which the aircraft flies. The pr... View full abstract»

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  • A passive millimeter wave camera for landing under low visibility conditions

    Publication Year: 1993, Page(s):109 - 115
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (724 KB)

    Passive millimeter wave (PMMW) focal plane array cameras are new sensors capable of imaging the forward scene under fog and low-visibility conditions at video frame rates. PMMW imaging sensors measure the blackbody radiation naturally emitted from the imaged scene. These cameras promise to be an effective aid, or an alternative, to existing technology for aircraft landing and surface operations un... View full abstract»

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  • The Motion Pictures Experts Group digital compression standard and its role in satellite systems

    Publication Year: 1993, Page(s):117 - 119
    Cited by:  Papers (1)  |  Patents (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (212 KB)

    The author discusses the general scope of audio and video compression and what role the Motion Pictures Experts Group (MPEG) standard has played in its development. The MPEG standard began in 1988 as an effort of the International Organization for Standardization (ISO) to develop a working standard for encoding and decoding compressed digital video. MPEG is also specifically addressed within the c... View full abstract»

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  • A new CFAR processor in nonhomogeneous background and multiple target situations

    Publication Year: 1993, Page(s):221 - 225
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (396 KB)

    The authors consider the problem of CFAR (constant false-alarm rate) detection in nonhomogeneous clutter and in multiple target situations. The data discriminator (DD) CFAR detector which performs two passes over the data, is proposed and analyzed. In the first pass, the algorithm senses possible interfering targets, and in the second pass the algorithm selects those samples which are identically ... View full abstract»

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  • Performance of coded QPSK modulation for the delivery of MPEG-2 stream compared to analog FM modulation

    Publication Year: 1993, Page(s):121 - 125
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (276 KB)

    The author compares the performance of coded quadrature phase-shift keying (QPSK) and analog frequency modulation (FM) for the delivery of video services by satellite. The proposed digital video scheme uses the Motion Picture Experts Group (MPEG-2) video compression with a concatenated coding. The performance of both systems is compared. The digital video scheme is shown to be more robust in noise... View full abstract»

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  • A versatile, broadband, low-profile antenna

    Publication Year: 1993, Page(s):227 - 231
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (400 KB)

    The recently invented spiral-mode microstrip (SMM) antenna is finding application in various commercial systems as well as various military systems in addition to the military application for which it was developed. The salient features of this antenna are reviewed with respect to those applications for which interest in the antenna has been strongest. The salient features of the new antenna are b... View full abstract»

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  • A 45-Mbits/sec. VLSI Viterbi decoder for digital video applications

    Publication Year: 1993, Page(s):127 - 130
    Cited by:  Papers (3)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (320 KB)

    The author describes the unique architecture and feature set incorporated into the STEL-2060 Viterbi Decoder, a VLSI device designed by Standford Telecom. This device was designed primarily for direct broadcasting by satellite (DBS) services and operates up to 45 Mb/s. The STEL-2060 uses industry standard, constraint length 7, polynomials and incorporates depuncturing circuitry to allow it to be u... View full abstract»

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  • FLAPS reflector antennas

    Publication Year: 1993, Page(s):233 - 238
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (644 KB)

    A flat parabolic surface (FLAPS) reflector is a thin (planar or conformal) surface consisting of an array of elements, each functioning as a radiator and phase shifter. Unlike a conventional planar array, however, the elements on the FLAPS surface are spatially fed using a feed assembly, as in a conventional reflector system. This results in an antenna technology that offers the advantages of both... View full abstract»

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  • Characterization of the PACSAT file broadcast system

    Publication Year: 1993, Page(s):71 - 79
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (604 KB)

    Since January 1990, amateur radio operators around the world have had the opportunity to use several low-Earth-orbit satellites providing store-and-forward communications services. The author focuses on the broadcast mode of operation as implemented on the PACSAT-1 and UoSAT-5 amateur radio satellites in 1992. The evolutionary process leading to the broadcast mode of operation is given along with ... View full abstract»

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  • Influence of various PCS spectrum allocation schemes on the ability to share spectrum with incumbent microwave users in the 1850-1990 MHz band

    Publication Year: 1993, Page(s):45 - 53
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (520 KB)

    The success of personal communication services (PCS) rests in the ability to share spectrum with incumbent microwave users in the 1850-1990-MHz band. Spectrum allocations from 20 MHz to 40 MHz per PCS licensee are being considered by the FCC. While it may be possible to make some spectrum available by negotiating relocation agreements with certain of the microwave users in a given MSA, local gover... View full abstract»

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  • The search and rescue communications channel-past, present and future

    Publication Year: 1993, Page(s):131 - 138
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (416 KB)

    From a macroscopic viewpoint, the underlying concept for search and rescue (SAR) involving radio beacons is a communications channel. The communications channel should establish a two-way link by providing confirmation of the message received. The author outlines the different aspects of the SAR communications channel from its very beginnings to the current COSPAS-SARSAT satellite system, and he a... View full abstract»

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  • A comparative study of JPEG and residual VQ compression of radar imagery

    Publication Year: 1993, Page(s):203 - 207
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (328 KB)

    The Joint Photographic Expert Group (JPEG) compression standard and a type of vector quantization called residual vector quantization (RVQ) are evaluated for the real-time compression of precision approach radar (PAR) video data. Experimental results obtained from simulated PAR imagery are presented which allow a performance and complexity comparison of the two compression methods. For low to mode... View full abstract»

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  • On adaptive arrays in mobile communication

    Publication Year: 1993, Page(s):55 - 58
    Cited by:  Papers (3)  |  Patents (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (236 KB)

    The author studies the use of adaptive arrays in mobile communication for increasing channel capacity as well as reducing co-channel interference. Antenna arrays may be used at the base station and/or at the mobile unit. A mathematical model for the received signal is presented and discussed in the context of frequency division multiple access (FDMA), time division multiple access (TDMA) and code ... View full abstract»

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  • High resolution MMW seeker fuse processing

    Publication Year: 1993, Page(s):175 - 179
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (316 KB)

    The authors describe a new signal processing technique for phased arrays that can be used in near-field target imaging. This processing technique is useful to millimeter wave seekers employing planar phased arrays as a new approach to performing warhead fusing. The array operation and signal processing are similar to synthetic sampled aperture radar (SSAMAR). Through a coherent integration of all ... View full abstract»

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  • Applications of the global positioning system to intelligent vehicle highway systems

    Publication Year: 1993, Page(s):139 - 141
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (228 KB)

    The Intelligent Vehicle Highway System (IVHS) program is aimed at reducing traffic congestion and motor vehicle emissions, and at improving highway safety, by applying advanced communications and computer technologies. The author examines the user requirements and system functions contemplated for IVHS, and discusses the surveillance and navigation services that are required to support them. Compa... View full abstract»

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  • Transportable orbital tracking, telemetry and command system

    Publication Year: 1993, Page(s):241 - 249
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (520 KB)

    NASA/Goddard Space Flight Center has implemented an automated ground-based telemetry, command, and Doppler system. Its function is to support the low-earth-orbiting satellite and sounding rocket programs. This fully transportable system can be configured with the capability to provide unmanned satellite support for seven days or operator augmented automated sounding rocket launch and tracking supp... View full abstract»

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  • Evaluation of candidate millimeter wave radars for synthetic vision

    Publication Year: 1993, Page(s):83 - 89
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (492 KB)

    In 1988 the US Federal Aviation Administration, in cooperation with industry, the US Air Force, the US Navy, and several other government organizations, initiated an effort to demonstrate the capabilities of existing technologies to provide an image of the runway and surrounding environment for pilots operating aircraft in low-visibility conditions. This effort was named the synthetic vision techn... View full abstract»

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